Sequences and debris files

HI all , I have a couple questions concerning the exporter and how the sequences seem to work .

I have set up and exported a few player characters with success and have managed to replace the stock forward and backward animations etc.. but I have made a sitting animation for our player so he can ride a horse {which I have exported basically as a player type character as well } but it doesnt seem to want to work or i should say , it doesnt seem to want to work the way I intend it too . I substituted it as both the jump and side animation to see if it would work and it only seems to work if i hit both at once or if i move backward then hit jump . I tried changing the priority levels , tried it with and without using the ground transform , tried it as a blend everything and it still wants to work it seems only when it wants too.
the best i have gotten it to work was when i used it as the forward animation worked everytime but it wouldnt work when we tried to make it run when the character mounted the horse .... any ideas ?

also how does the debris file work?